The President of the United States of America, authorized by Act of Congress, July 9, 1918, takes pleasure in presenting the Distinguished Service Cross to First Lieutenant (Infantry) Donald S. Mackay, United States Army, for extraordinary heroism in action while serving with 168th Infantry Regiment, 42d Division, American Expeditionary Forces, near Sergy, France, July 26 – 30, 1918. In an effort to locate enemy machine-gun emplacements, Lieutenant Mackay constantly exposed himself to enemy fire and, while so doing, was severely wounded. During the entire five days of operations he led a scout group forward, locating nests that had been stubbornly resisting the progress of our troops and supplying the artillery with most valuable information, resulting in the destruction of the nests.